Silicone-Hydrogel lenses

[Eli]

Thanks for your earlier response Dr. G.,
I should probably know this this by now, but what brands of lenses are silicone-hydrogel based? As I think I mentioned earlier, I used to wear Proclear Torics, but they got uncomfortable in dry weather fairly quickly. Also, I have MGD and therefore (I assume) a compromised lipid layer in my tear film. Can the right contact lens kind of act as a temporary lipid layer and help delay the evaporation of tears? Or does a healthy lipid layer generally have to be present to wear contacts comfortably? So many questions, so little time!
Thank you
Eli

[DrG]

Dear Eli,

I didn't mean to ignore your question, and it was a good one. I do believe that a contact lens can act as a lipid layer substitute. I think of them as moisture barriers which act as shields to protect the cornea from the external environment. But, they are still prone to evaporation and dryness, which is why rewetting drops are still needed. I have seen patients go from one drop every 5 minutes to one drop every hour simply by wearing a bandage lens.

I have developed some interesting evaporation curves for the various brands of contact lenses.

It really depends on what stage you are at in your dry eye as to whether the lens will help or not. Many dry eye patients like the silicone hydrogels, but patients who can wear Proclears LOVE them. The two groups are frequently not interchangeable.